Background: Corneal neovascularization is a major cause of blindness worldwide. The objective of our research is to identify the role of collagen XVIII and its proteolytic fragments in corneal neovascularization. Our laboratory has found that MMP-7 cleaves corneal and recombinant collagen XVIII to generate a 28 kDa fragment which may regulate corneal neovascularization during corneal wound healing. Hypothesis: Activated MMP-7 in cornea may contribute to the production of endostatin and endostatin-spanning fragments, which inhibit corneal neovascularization. Specific Aims: A. To determine the distribution of endostatin and MMP-7-derived proteolytic fragment of collagen XVIII in the cornea in vivo and in vitro. B. To characterize the function of endostatin and MMP-7-derived proteolytic fragment of collagen XVIII in vascular endothelial cell proliferation, migration, and tube formation in vitro. C. To characterize the role of endostatin and MMP-7-derived proteolytic fragment of collagen XVIII in corneal neovascularization in vivo. Significance: Understanding the mechanisms that maintain corneal avascularity may allow us to prevent blindness caused by corneal neovascularization. The study of endostatin and MMP-7 in the cornea may provide valuable information about their possible clinical significance in corneal neovascularization and wound healing.